1. Field of the Invention
This invention relates generally to expansible watchbands, and is concerned in particular with an improved end connector assembly for coupling the ends of such watchbands to watches having watch cases which may either be metallic or molded from plastic materials such as for example ABS.
2. Description of the Prior Art
The conventional expansible watchband typically includes a row of top links overlying a row of bottom links, with each bottom link being interconnected to two adjacent top links by pairs of U-shaped staples. Springs housed in the links coact with the staples to yieldably contract the band. The top and bottom links as well as the staples and springs are typically fabricated as metal stampings, and the top links are usually covered with decorative metallic top shells.
In the past, as disclosed for example in U.S. Pat. No. 4,958,334 (Grosjean), such watchbands have been coupled to plastic watch cases by end connectors employing both metallic and plastic components. The plastic component consists of an insert captured between top and bottom metallic plates. The top plate is configured and decoratively finished, often by gold plating, to comport in appearance with the decorative top shells of the watchband. The plastic insert serves to isolate the plastic watch case from damaging frictional contact with the metallic components of the end connector.
The plastic insert is provided with forwardly projecting mutually spaced lugs configured and dimensioned for assembly in a mortise and tenon relationship with a mating set of mutually spaced lugs projecting from the side of the watch case. Apertures in the thus assembled lugs are aligned to receive a metallic pin which serves to pivotally join the end connector to the watch case. The lugs of the plastic insert serve to grip and hold the pin in place.
The top plate of the end connector assembly includes forwardly projecting flanges which during assembly are rolled around the plastic lugs of the insert, thereby concealing the plastic lugs from view while at the same time contributing to the secure mechanical coupling of the insert between the metallic top and bottom plates of the connector.
There are several drawbacks associated with this arrangement. For example, when rolling the forwardly projecting flanges of the top plate around the lugs of the plastic insert, it is difficult to achieve uniformity and precision because the plastic lugs are relatively soft and deformable and as such, do not provide stable platforms during the bending operation. Also, in order to provide flanges with sufficient lengths to reach around the plastic lugs, the overall length of the top plate must be increased. Because the material of the top plate is usually plated or otherwise expensively finished, any increase of its dimensions contributes unfavorably to the cost of the end connector. Pronounced bending of the top flanges can also cause cracking of the plated surfaces of the top plate.